This invention relates to an electric connection box on which an electronic control unit for an automobile, together with electrical parts (such as relays and fuses), are mounted, and the invention also relates to a method of assembling this electric connection box.
As examples of the related art relating to this kind of electric connection box, there are known those shown in FIGS. 10 to 13 (for example, Patent Literatures 1 to 4).
FIG. 10 (Patent Literature 1) shows a wiring structure of a relay box (electric connection box) 53 which is to be combined with a mating fuse box 50. Fuses 52 are received in the fuse body 50, and relays 54 are received in the relay box 53. The boxes 50 and 53 are combined together by engaging an engagement portion 51, formed on a side wall of the fuse box 50, in an engagement reception portion 55 formed on a side wall of the relay box 53.
A harness-passing through hole is formed through one side wall of the relay box 53, and a wire harness 58 is passed through this through hole, and one end portion of this wire harness is extended to the exterior through a through hole 56 formed through another side wall. The thus outwardly-extended wire harness 58 is connected via connectors 57 to the fuses 52 within the fuse box 50.
FIG. 11 (Patent Literature 2) shows a box body 60 of an electric connection box in which a plurality of connectors are mounted. The box body 60 is made of a synthetic resin, and mounting portions 62 on which connectors can be mounted, respectively, are formed integrally on an inner surface 61 of this box body. A lock portion 63 for engagement with a lock portion of the corresponding connector is formed within each of the mounting portions 62.
With respect to the specification of the mounting portions 62, these mounting portions have the same shape, and therefore the connectors can be mounted in a suitable layout on the box body 60 so as to suitably meet a change in circuitry or specification.
FIG. 12 shows a lock structure of relay boxes (electric connection boxes) 65 and 67. Pairs of convex thickened portions 66 and 66, each having a guide groove 66a, are formed on one outer surface of one relay box 65, and fitting plate portions 68 for the pairs of guide grooves 66a and 66a are formed integrally on the other relay box 67.
The fitting plate portion 68 is connected through an interconnecting piece portion 68b to bottom portions of a pair of guide ribs 70 and 70 formed on and projecting from one outer surface of the relay box. A slit 71 is formed in a central portion of the fitting plate portion 68, and a pair of right and left elastic piece portions 68a and 68a are formed as a result of formation of this slit 71. The pair of elastic piece portions 68a and 68a have elasticity in a direction of the length of the relay box, and also have elasticity in a direction of the thickness of the fitting plate portion 68. Therefore, when the pair of elastic piece portions 68a and 68a are inserted into the pair of guide grooves 66a and 66a, respectively, the elastic piece portions 68a are elastically deformed, and are fitted respectively in these guide grooves without shaking because of their restoring force.
FIG. 13 (Patent Literature 4) shows a lock cancellation structure of a connector. A pair of lock cancellation piece portions 76 and 76 are formed at a distal end portion of an elastic retaining piece portion 75 formed by notching a wall of a connector housing. A retaining projection 75a for engagement with an engagement projection on a mounting panel is formed on an outer surface of the elastic retaining piece portion 75.
Each lock cancellation piece portion 76 has a slanting surface 76a, and when an inserted lock cancellation tool 77 presses the slanting surface 76a, the lock cancellation piece portions 76 are elastically deformed into a fitting space in the connector housing, so that the locking engagement of the retaining projection 75a with the engagement projection is canceled.
Patent Literature 1
JP-A-8-47144
Patent Literature 2
JP-UM-A-59-82975
Patent Literature 3
JP-UM-A-3-7602
Patent Literature 4
JP-UM-A-3-35674
However, the electric connection boxes, the lock structures, etc., shown in the above conventional examples, have the following problems which should be solved.
In the wiring structure of the relay box 53 of the first conventional example, the wire harness 53, which passes through the interior of the relay box 53, and is extended to the exterior, is connected via the connectors 57 to the fuses 52 within the fuse box 50. During the transport of the relay box 53, the wire harness 58, extended to the exterior, hangs in midair, and therefore the wire harness 58 can be entangled, and the connectors 57 can be caught by the wire harness 58, and the connectors 57 can interfere with other part to be damaged.
In the box body 60 of the electric connection box shown in the second conventional example, the amount of projecting of each mounting portion 62 from the inner surface 61 is so large that an excessive gap is formed between the mounted connector and the inner surface 61, and this invites a problem that a part-mounting space can not be effectively utilized.
In the lock structure of the relay boxes 65 and 67 shown in the third conventional example, each fitting plate portion 68, having the pair of elastic piece portions 68a and 68a, is inserted into the guide grooves 66a provided at the outer surface of the one relay box 65, thereby preventing the pair of relay boxes 65 and 57 from shaking relative to each other. However, the convex thickened portions 66, each having the guide groove 66a, project outwardly from the outer surface, and therefore during the transport, the convex thickened portions 66 can interfere with other part to be deformed.
In the lock cancellation structure of the connector shown in the fourth conventional example, when the lock cancellation piece portion 76, formed at the distal end portion of the elastic retaining piece portion 75, is pressed by the lock cancellation tool 77, the elastic retaining piece portion 75 is elastically deformed, thereby canceling the locking engagement of the retaining projection 75a with the engagement projection. However, a space for the insertion of the bar-like lock cancellation tool 77 thereinto need to be provided at the inner side of a generally U-shaped sliding rail, and therefore the amount of projecting of the sliding rail must be made relatively large, and this invites a problem that an extra gap is formed between the connector and the inner surface.